Last year, the Drug Enforcement Administration rejected a petition by medical marijuana advocates to change the classification.

The court said that the question wasn't whether marijuana could have some medical benefits, but rather whether the DEA's decision was "arbitrary and capricious." The court concluded that the DEA action survives review under that standard.

Marijuana is classified as a controlled substance, categorized as having a high potential for abuse and no currently accepted medical use, together with drugs like heroin, LSD and ecstasy.